新概念文化大爆炸：百慕大魔鬼三角之謎

Ships, airplanes, helicopters and men - they have all been sucked into the Bermuda Triangle at some point of time or the other. None of them have ever returned. It is impossible to provide details of the first such disappearance because of erratic record keeping over the years, but it was the U.S. Navy that first brought the Bermuda Triangle mystery into the limelight.

On 5 December 1945, five Avenger torpedo bombers of the US Navy took off from Fort Lauderdale on a routine training flight over the Atlantic. They did not return. A large Mariner flying boat sent to search for the missing aircraft also failed to return. No trace has ever been found of the six planes or the 27-crew members. As a result of this incident, it was discovered that quite a few ships and aircraft had also been lost, apparently without explanation in the triangular area off the south-east coast of the United States bounded by Bermuda, Puerto-Rico and Florida.

Every investigator worth his salt has postulated a number of theories that attempt to satisfactorily explain the mysterious happenings at the Bermuda triangle. Some of the more bizarre explanations include extra-terrestrials, the presence of a huge magnet, the position of the moon, sudden appearing of giant waves, time/space warps, electrostatic charges, and the return of the inhabitants of the lost city Atlanta. There have been innumerable books that have been written regarding the unusual phenomenon which take place in this area.

One of the more credible theories seems to belong to Dr Richard McIver, who centers his explanation on the presence of methane hydrate. Methane hydrate was first encountered in the 1920s and 1930s in the early days of the American and Soviet gas industries. Natural gases (a mixture of flammable gases found in the Earth's crust, methane, ethane, butane and propane) were being piped across the Atlantic but occasionally the pipes would become mysteriously plugged up.

All gases except for helium, hydrogen and neon can form hydrates if enough gas and water are present, if the pressure is high enough and if the temperature is low enough. These conditions can be found naturally occurring on earth, and methane hydrate has been found to exist in huge quantities in many parts of the sea floor and is concentrated in some places on continental slopes such as the Bermuda Triangle. The structure of the molecule of methane hydrate is such that it facilitates the capturing of a large amount of gas. If this were to break-up, then even a small area could cause a large gas release.

Sediment piles on continental slopes have the tendency to accumulate on the slopes of the edge of continental plates. But it is unstable and can tumble down. When this happens, it can cause the removal of the hydrate layer, releasing the methane gas trapped below. Methane gas bubbling up through the sea will cause an area of decreased density; ships will lie lower in the water and will be swamped by the least wave; also methane gas when mixed with air in the correct proportions is highly explosive. This could account for the mysterious disappearances of both ships and aircraft.

All this activity on the sea bed occurs at the edges of tectonic plates, where there is constant activity as a result of the pressures beneath the earth's crust; any wreckage sinking to the bottom would be lost forever beneath the moving plates.

The latest myth that is doing the rounds is that there have been disappearances in the Indian and Pacific oceans, this means that the Bermuda Triangle is widening in scope.